Numerical simulation of temperature field, fluid flow and weld bead formation in oscillating single mode laser-GMA hybrid welding

A three dimensional numerical model of oscillating single mode laser-GMA hybrid welding process with lap joint and arc inclination configuration has been developed for the first time. The model is used to investigate the temperature field and fluid flow corresponding to the aforesaid welding process and weld configuration. An asymmetric distribution of arc heat and a cylindrical volumetric distribution of laser heat are established to describe the heat transfer from the combined heat source to the workpieces. The droplet with predefined temperature and velocity is impinged on the weld pool at a given fillet weld angle. Arc pressure, electromagnetic force, Marangoni force and buoyancy are also considered in the model with some modifications with respect to the lap joint and arc inclination configuration. Results show that the droplet impingement process has a significant influence on the weld geometry, temperature field and fluid flow pattern due to the transfer of mass, energy and momentum into the weld pool. These unique temperature fields and flow patterns are characteristic to the lap joint and arc inclination configuration. The proposed model exhibits close correspondence with the experimental results with respect to weld geometry.